UBC Theses and Dissertations

UBC Theses Logo

UBC Theses and Dissertations

Behavioural and physiological responses of Steller sea lions to invasive marking techniques : evidence of post-operative pain Walker, Kristen Amy


Marine mammal research often requires marking and tracking animals to collect long-term ecological data, but these procedures may cause pain. The aim of this thesis was to assess the behavioural and physiological effects of invasive marking and tracking techniques used on marine mammals. This thesis consists of 7 chapters, beginning with a general introduction (Ch. 1) and ending with a general discussion (Ch. 7). Chapter 2 reviews the literature on short- and long-term effects of marking and tagging, concluding that the preponderance of studies focus on injuries and behavioural changes and that no research prior to this thesis has assessed post-operative pain in marine mammals. Chapters 3 to 6 describe experiments designed to fill this gap by focussing on pain responses of endangered Steller sea lions to invasive marking (hot-iron branding) and tracking (implanting a tracking device via intra-abdominal surgery) procedures. Seven behaviours associated with post-operative pain were monitored for 3 d pre- up to 12 d post-surgery with the aim of describing behavioural responses after abdominal surgery (Ch. 3) and comparing the efficacy of two analgesic treatments (Ch. 4). In both studies sea lions spent more time with their back arched and standing, and spent less time lying on the ventral side and in locomotion after surgery, regardless of analgesic treatment. Chapter 5 described the behavioural responses of sea lions after hot-iron branding. In the 3 days after branding sea lions spent more time grooming their branded area, less time with pressure on their branded side, and less time in the pool and in locomotion. Chapter 6 assessed physiological (breathing and heart rate) and behavioural responses of anaesthetised sea lions during hot-iron branding. Sea lions had increased heart and breathing rate during and in the minutes after hot-iron branding. Behavioural responses during branding included trembling and head and shoulder movements. These findings illustrate behavioural and physiological responses that can be applied to assessing pain in sea lions, and suggest that more effective analgesic protocols are required to mitigate pain responses after hot-iron branding and abdominal surgery.

Item Media

Item Citations and Data


Attribution-NonCommercial-NoDerivs 3.0 Unported